1. Field of the Invention
This invention relates to a developer collection vessel for collecting a developer and an image formation apparatus comprising the developer collection vessel and in particular to an image formation apparatus comprising a full condition detector for detecting the collection vessel being full of developer.
2. Description of the Related Art
In an electrophotographic image formation apparatus applied to a printer, a copier, etc., developers to be discharged occur in a photoconductor, a transfer roll, a developing machine, etc., and need to be collected, and a collection vessel is placed. When the collection vessel becomes full of the collected developers, it should be replaced and a full condition detector is provided for detecting the collection vessel being full of developer.
Hitherto, as an image formation apparatus comprising this kind of collection vessel, an apparatus has been disclosed in JP-A-62-94883. In the related art example, a transparent or semi-transparent housing is expanded upward on the top of the collection vessel and optical sensors comprising a light emission element and a light reception element are placed on both sides of the housing. A float member is placed in the collection vessel so that it can move up and down. When a collected developer enters the collection vessel, the collected developer presses the float member and causes the float member to rise. A light shield member fixed to the float member is inserted into the housing and blocks light from the optical sensor, whereby a full condition is detected.
However, in the related art example, the full condition detector moves the float member up in response to the amount of the collected developer. Thus, if moving up of the float member is inhibited for some reason, it is made impossible to detect a full condition; developer clogging occurs and there is a fear of incurring a serious accident. Since the float member is used, there is a problem of complicating the structure.
It is therefore an object of the invention to provide a developer collection vessel and an image formation apparatus comprising a full condition detector capable of reliably detecting a full condition according to a simple configuration.
To the end, according to a first aspect of the invention, there is provided a developer collection vessel comprising a collection port to which a discharge section where a developer is discharged is connected, a collection space connected to the collection port, and at least one component of a full condition detector for detecting a full condition of developer based on the developer overflowing the collection space. Therefore, a full condition is detected based on the developer overflowing the collection space, so that a full condition can be detected reliably and the structure can also be simplified.
Preferably, one component of the full condition detector provided in the collection vessel is placed on the bottom of a collection vessel main unit. Accordingly, the effective use of space can be made and it is made possible to reduce the whole image formation apparatus. The component is formed of, for example, a translucent detection vessel, and the developer entered in the detection vessel can be detected by an optical sensor. Preferably, the detection vessel is joined with joint means that can be easily attached to and detached from the collection vessel main unit, such as adhesive tape.
According to a second aspect of the invention, there is provided a developer collection vessel comprising a plurality of collection ports to which a plurality of discharge sections where a developer is discharged are connected, a plurality of collection spaces connected to the plurality of collection ports, a communication part for communicating with the plurality of collection spaces, and at least one component of a full condition detector, placed below the communication part, for detecting a full condition of developer based on the developer overflowing any of the collection spaces. Therefore, the developers entered from the plurality of discharge sections through the collection ports in the collection spaces are piled up in the corresponding collection spaces. When the developer overflows one of the collection spaces, the developer is sent through the communication part to the full condition detector, so that only one full condition detector is required and the configuration can be simplified.
The collection capacities of the collection spaces can be defined according to the heights and shapes of the partition walls. Preferably, the collection spaces have collection capacities set so as to become almost equal to the ratio of the collected developers to be discharged for making the effective use of the space in the collection vessel. However, to reliably detect a full condition, preferably one collection space has a collection capacity set so that the developer overflows the collection space earlier than any other collection space, and the full condition detector is placed adjacent to the collection space that the developer overflows earliest.
According to a third aspect of the invention, there is provided an image formation apparatus comprising a collected developer occurrence section where developer to be collected occurs, a discharge section being connected to the collected developer occurrence section, a collection vessel having a collection port to which the discharge section is connected and a collection space connected to the collection port, and a full condition detector for detecting a full condition of developer based on the developer overflowing the collection space of the collection vessel.
The full condition detector can be made up of the detection vessel placed in the collection vessel and the sensor section placed in the image formation apparatus main unit. Preferably, the collection vessel is placed on the front of the image formation apparatus main unit. Further, preferably the detection vessel is provided with an opening/closing mechanism for opening/closing the open portion of the detection vessel in conjunction with attaching, detaching the collection vessel, so that only the collected developer when a full condition is detected is introduced into the detection vessel.